From 5f124efb3e090f96f217bee22f3c8897f9772f14 Mon Sep 17 00:00:00 2001
From: yliu <yliu@apache.org>
Date: Fri, 23 Jan 2015 02:37:44 +0800
Subject: [PATCH] HDFS-7660. BlockReceiver#close() might be called multiple
 times, which causes the fsvolume reference being released incorrectly. (Lei
 Xu via yliu)

---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt                   | 4 ++++
 .../org/apache/hadoop/hdfs/server/datanode/BlockReceiver.java | 3 ++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 74eb160695..9176ec7ecc 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -768,6 +768,10 @@ Release 2.7.0 - UNRELEASED
     HDFS-3519. Checkpoint upload may interfere with a concurrent saveNamespace.
     (Ming Ma via cnauroth)
 
+    HDFS-7660. BlockReceiver#close() might be called multiple times, which
+    causes the fsvolume reference being released incorrectly. (Lei Xu via
+    yliu)
+
 Release 2.6.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockReceiver.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockReceiver.java
index 12041a60ae..3d37df5746 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockReceiver.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockReceiver.java
@@ -123,7 +123,7 @@ class BlockReceiver implements Closeable {
   private boolean syncOnClose;
   private long restartBudget;
   /** the reference of the volume where the block receiver writes to */
-  private final ReplicaHandler replicaHandler;
+  private ReplicaHandler replicaHandler;
 
   /**
    * for replaceBlock response
@@ -334,6 +334,7 @@ public void close() throws IOException {
     }
     if (replicaHandler != null) {
       IOUtils.cleanup(null, replicaHandler);
+      replicaHandler = null;
     }
     if (measuredFlushTime) {
       datanode.metrics.addFlushNanos(flushTotalNanos);